ONSIDE Complete Soccer is an early 3D soccer game that includes four playing leagues (England, French, German and Italian) and a basic managerial options, where the player can trade players, deal with finances and stadium expansions. The key features of the game include several camera options, seasonal weather with progressive pitch damage, indoor five-a-side and play-by-play commentary including all player names. Graphics feature a polygonal stadium with sprite (2D) players.

Gameplay features a typical two-button layout, with one button to play low balls and other to kick higher balls (including crosses and shooting on goal), and by holding both the player can sprint, making him much harder to stop. It's possible to score goals from most situations, from distance kicks, crosses, outpacing the goalkeeper and from dead ball situations, where the player can also tweak player positions in a blackboard.